Dubbo入门学习二：Dubbo的泛化调用

泛化接口调用方式主要用于客户端没有API 接口及模型类元的情况，参数及返回值中的所有 POJO均用 Map 表示，通常用于框架集成，比如：实现一个通用的服务测试框架，可通过 GenericService调用所有服务实现。

服务提供者

1.Spring配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"
       xmlns="http://www.springframework.org/schema/beans"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
       http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">

    <!-- provider's application name, used for tracing dependency relationship -->
    <dubbo:application name="demo-provider"/>

    <!-- use multicast registry center to export service -->
    <dubbo:registry protocol="zookeeper" address="localhost:2181"/>

    <!-- use dubbo protocol to export service on port 20880 -->
    <dubbo:protocol name="dubbo" port="20880"/>

    <!-- service implementation, as same as regular local bean -->
    <bean id="demoService" class="com.alibaba.dubbo.demo.provider.DemoServiceImpl"/>

    <!-- declare the service interface to be exported -->
    <dubbo:service version="1.0.0" interface="com.alibaba.dubbo.demo.DemoService" ref="demoService"/>

</beans>

2.服务提供类

package com.alibaba.dubbo.demo.provider;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Provider {
    public static void main(String[] args) throws Exception {
        System.setProperty("java.net.preferIPv4Stack", "true");
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"META-INF/spring/dubbo-demo-provider.xml"});
        context.start();
        System.in.read(); // press any key to exit
    }
}

服务调用者—API调用方式

泛化实现类-GenericConsumer

package com.alibaba.dubbo.demo.consumer;

import com.alibaba.dubbo.config.ApplicationConfig;
import com.alibaba.dubbo.config.ReferenceConfig;
import com.alibaba.dubbo.config.RegistryConfig;
import com.alibaba.dubbo.rpc.service.GenericService;

public class GenericConsumer {
    public static void main(String[] args) {
        ReferenceConfig<GenericService> reference = new ReferenceConfig<GenericService>();
        // 弱类型接口名
        reference.setInterface("com.alibaba.dubbo.demo.DemoService");
        reference.setVersion("1.0.0");
        // 声明为泛化接口
        reference.setGeneric(true);

        //应用名称
        ApplicationConfig application = new ApplicationConfig("demo-consumer");
        reference.setApplication(application);

        //初始化dubbo注册中心配置
        RegistryConfig registry = new RegistryConfig();
        registry.setProtocol("zookeeper");
        registry.setAddress("127.0.0.1:2181");
        reference.setRegistry(registry);
        // 用com.alibaba.dubbo.rpc.service.GenericService可以替代所有接口引用
        GenericService genericService = reference.get();

        // 基本类型以及Date,List,Map等不需要转换，直接调用
        Object result = genericService.$invoke("sayHello", new String[] {"java.lang.String"}, new Object[] {"nezha-world"});
        System.out.println("================="+result);
    }
}

服务调用者—Spring配置方式

1.dubbo-demo-generic-consumer.xml

配置文件路径：resources目录下--->>>``META-INF/spring/dubbo-demo-generic-consumer.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"
       xmlns="http://www.springframework.org/schema/beans"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
       http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">

    <!-- consumer's application name, used for tracing dependency relationship (not a matching criterion),
    don't set it same as provider -->
    <dubbo:application name="demo-consumer"/>

    <!-- use multicast registry center to discover service -->
    <dubbo:registry protocol="zookeeper" address="127.0.0.1:2181"/>

    <!-- generate proxy for the remote service, then demoService can be used in the same way as the
    local regular interface -->
    <dubbo:reference version="1.0.0" id="demoService" generic="true" interface="com.alibaba.dubbo.demo.DemoService"/>
</beans>

2.GenericConsumer

package com.alibaba.dubbo.demo.consumer;

import com.alibaba.dubbo.rpc.service.GenericService;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class GenericConsumer {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"META-INF/spring/dubbo-demo-generic-consumer.xml"});
        context.start();
        GenericService genericService = (GenericService) context.getBean("demoService");
        Object result = genericService.$invoke("sayHello", new String[] {"java.lang.String"}, new Object[] {"nezha-world"});
        System.out.println("================="+result);
    }
}

参考文献

1.Dubbo官方使用手册—泛化的使用